Identifying painting - 2 people embracing. Uses a single line

I don't know, but it looks a lot like a sketch by Picasso, he used to do that sort of thing.

I agree; it looks a lot like Picasso. But other artists come to mind as well. Here's Saul Steinberg:

It's not like they didn't knock stuff like that out all the time. Lowry used to give out sketches to taxi drivers and waiters in lieu of payment and I doubt he was the only one.

Unless you're lucky enough to hit the right artist you're not goiung to be any the wiser. I googled Picasso sketches and a ton of stuff came up, just not the piece in question.